Benjamin H. Taragin

Hypogastric artery coil embolization prior to endoluminal repair of aneurysms and fistulas: buttock claudication, a recognized but possibly preventable complication.

PURPOSE Hypogastric artery embolization is considered to be necessary to prevent retrograde flow and potential endoleaks when a stent-graft crosses the origin of the hypogastric artery. The authors assess the incidence of buttock claudication, which is the primary complication encountered. The effect of coil location and the presence of antegrade flow at the completion of embolization are evaluated. MATERIALS AND METHODS Hypogastric artery embolization and endoluminal repair of aneurysms and fistulas was performed in 34 patients (30 men; four women) aged 27-91 years (mean, 76 years). Ten patients were being treated for solitary abdominal aortic aneurysms, 13 were being treated for aortoiliac aneurysms, and six patients were being treated for isolated common iliac aneurysms, three for hypogastric artery aneurysms and two for iliac arteriovenous fistulas. Eleven patients had coils placed completely above the bifurcation of the hypogastric artery and 23 patients had coils placed at the bifurcation, or within the branches of the hypogastric artery. Preservation of antegrade flow after embolization was noted in 14 of 34 patients. RESULTS Thirty-four patients underwent stent-graft repair after hypogastric artery embolization. There were two perioperative deaths, three proximal leaks, and one collateral leak. Of the 32 patients who survived the procedure, there was one retrograde leak, even though 13 of 32 (41%) patients had continued antegrade flow at completion of the hypogastric artery embolization. When coils were placed at or in the bifurcation of the hypogastric artery, 12 of 22 (55%) experienced claudication. When coils were placed in the proximal hypogastric artery, one of 10 (10%) claudicated. CONCLUSION It is probably not necessary to completely occlude antegrade flow in the hypogastric artery to prevent a distal endoleak. Buttock claudication is rare when coils are placed in the proximal hypogastric artery rather than at its bifurcation or in its branches.

Comparison of Ultrasound and CT in the Evaluation of Pneumonia Complicated by Parapneumonic Effusion in Children

OBJECTIVE The purpose of our study was to compare chest ultrasound and chest CT in children with complicated pneumonia and parapneumonic effusion. MATERIALS AND METHODS We retrospectively compared chest ultrasound and chest CT in 19 children (nine girls and 10 boys; age range, 8 months-17 years) admitted with complicated pneumonia and parapneumonic effusion between December 2006 and January 2009. Images were evaluated for effusion, loculation, fibrin strands, parenchymal consolidation, necrosis, and abscess. In the subset of patients who underwent surgical management, imaging findings were correlated with operative findings. RESULTS Eighteen of 19 patients had an effusion on both chest ultrasound and chest CT. The findings of effusion loculation as well as parenchymal consolidation and necrosis or abscess were similar between the two techniques. Chest ultrasound was better able to visualize fibrin strands within the effusions. Of the 14 patients who underwent video-assisted thoracoscopy, five had surgically proven parenchymal abscess or necrosis. Preoperatively, chest ultrasound was able to show parenchymal abscess or necrosis in four patients, whereas chest CT was able to show parenchymal abscess or necrosis in three. CONCLUSION In our series, chest ultrasound and chest CT were similar in their ability to detect loculated effusion and lung necrosis or abscess resulting from complicated pneumonia. Chest CT did not provide any additional clinically useful information that was not also seen on chest ultrasound. We suggest that the imaging workup of complicated pediatric pneumonia include chest radiography and chest ultrasound, reserving chest CT for cases in which the chest ultrasound is technically limited or discrepant with the clinical findings.

Maximizing time-resolved MRA for differentiation of hemangiomas, vascular malformations and vascularized tumors

Contrast-enhanced magnetic resonance angiography (MRA) using time-resolved imaging is a relatively new and increasingly popular technique. We will describe the technique utilized at our institution, Time-Resolved Imaging of Contrast Kinetics (TRICKS; GE Healthcare, Milwaukee, WI), and the parameters that can be adjusted to optimize the exam. We will review key imaging features of hemangiomas and vascular malformations in various modalities, with a special emphasis on the TRICKS appearance.

MRI findings in pediatric patients with scurvy

In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia.

Value of Focused Appendicitis Ultrasound and Alvarado Score in Predicting Appendicitis in Children: Can We Reduce the Use of CT?

OBJECTIVE The purpose of this study was to evaluate the effectiveness of focused appendicitis ultrasound combined with Alvarado score to accurately identify appendicitis in children in whom it is suspected, thereby reducing unnecessary CT examinations and associated radiation exposure. MATERIALS AND METHODS We retrospectively evaluated the focused appendicitis ultrasound, CT, clinical, and laboratory findings of 522 consecutively registered children (231 boys, 291 girls; mean age, 13.04 [SD, 5.02] years; range, 0.74 months-21 years) who underwent focused appendicitis ultrasound for abdominal pain in a pediatric emergency department from January 2008 through October 2009. All children underwent surgery or clinical follow-up to exclude missed appendicitis. Sonographic findings were characterized as positive, negative, or inconclusive (appendix not visualized). Alternative diagnoses were noted. Alvarado score (0-10 points based on multiple clinical criteria) was determined. Focused appendicitis ultrasound and Alvarado score results were compared with surgical and pathologic reports. RESULTS Both focused appendicitis ultrasound results and Alvarado score were associated with likelihood of surgery for appendicitis (p = 0.0001). Focused appendicitis ultrasound had conclusive results: 105 positive and 27 negative in 132 of 522 (25.2%) children. In the 390 of 522 (74.7%) children with inconclusive focused appendicitis ultrasound findings, 43 of 390 (11.0%) eventually had a diagnosis of appendicitis with CT (n = 26) or Alvarado score (n = 17). Among children with inconclusive focused appendicitis ultrasound findings and an Alvarado score less than 5 (241/522, 46.1%), only one patient had appendicitis. The negative predictive value (NPV) of inconclusive ultrasound findings and low Alvarado score combined was 99.6%. Among children with inconclusive focused appendicitis ultrasound findings and an Alvarado score of 5-8, the NPV decreased to 89.7%. CONCLUSION Children with inconclusive focused appendicitis ultrasound findings and a low Alvarado score are extremely unlikely to have appendicitis (NPV, 99.6%). Avoiding unnecessary CT of these patients is a safe approach to diagnosis.

Appropriateness of imaging studies ordered by emergency medicine residents: Results of an online survey

OBJECTIVE The purpose of this study is to determine the proficiency of emergency medicine residents in selecting appropriate radiologic examinations for specific clinical scenarios and to ascertain whether their training improves competency in this area over the course of their residency. MATERIALS AND METHODS An online multiple-choice questionnaire was created. It included 10 clinical scenarios excerpted from the American College of Radiology Appropriateness Criteria guidelines and instructed residents to select the most appropriate initial imaging study. A link and invitation to the survey were e-mailed to the residency program directors and coordinators of all American Council for Graduate Medical Education-accredited emergency medicine residency training programs with the request that they be forwarded to their current residents. Responses were graded, with correct answers derived from the American College of Radiology guidelines. Results were stratified by year of emergency medicine training, and an analysis of variance was performed. RESULTS A total of 583 residents from at least 77 different emergency medicine residency training programs completed the survey. Overall, the average number of questions answered correctly was 7.1 of 10 (SD, 1.2). First-through fourth-year residents averaged 6.9 (SD, 1.3), 7.1 (SD, 1.2), 7.1 (SD, 1.1), and 7.5 (SD, 1.1) correct answers, respectively. Analysis of variance found no significant difference between the scores of the four classes (p = 0.09). CONCLUSION Emergency medicine residents do not show significant improvement over the course of their residency in their ability to choose appropriate imaging studies. This finding suggests that there is a role for more-rigorous focused instruction to better familiarize residents with appropriateness guidelines for diagnostic imaging selection.

Retained fibrin sheaths: chest computed tomography findings and clinical associations.

Purpose: Fibrin sheaths may develop around long-term indwelling central venous catheters (CVCs) and remain in place after the catheters are removed. We evaluated the prevalence, computed tomographic (CT) appearance, and clinical associations of retained fibrin sheaths after CVC removal. Materials and Methods: We retrospectively identified 147 adults (77 men and 70 women; mean age 58 y) who underwent CT after CVC removal. The prevalence of fibrin sheath remnants was calculated. Bivariate and multivariate analyses were performed to assess for associations between sheath remnants and underlying diagnoses leading to CVC placement; patients’ age and sex; venous stenosis, occlusion, and collaterals; CVC infection; and pulmonary embolism. Results: Retained fibrin sheaths were present in 13.6% (20/147) of cases, of which 45% (9/20) were calcified. Bivariate analysis revealed sheath remnants to be more common in women than in men [23% (16/70) vs. 5% (4/77), P=0.0018] and to be more commonly associated with venous occlusion and collaterals [30% (6/20) vs. 5% (6/127), P=0.0001 and 30% (6/20) vs. 6% (7/127), P=0.0003, respectively]. Other variables were not associated. Multivariate analysis confirmed the relationship between fibrin sheaths and both female sex (P=0.005) and venous occlusion (P=0.01). Conclusions: Retained fibrin sheaths were seen on CT in a substantial minority of patients after CVC removal; nearly half of them were calcified. They were more common in women and associated with venous occlusion.

Identifying intestinal malrotation on magnetic resonance examinations ordered for unrelated indications

BackgroundAnatomical imaging findings indicating normal bowel rotation can be identified on cross-sectional imaging, including magnetic resonance imaging (MRI) performed for non-related indications.ObjectiveThe goal of our study was to assess whether non-targeted MRI can accurately assess intestinal malrotation.Materials and methodsFour anatomical landmarks were assessed on MRIs of the chest, spine or abdomen performed from January 2006 to June 2014, on patients who also had upper gastrointestinal series (UGI) performed within 10 years of the MRI date: 1) retroperitoneal duodenum, 2) left upper quadrant duodenojejunal junction, 3) superior mesenteric artery to the left of the superior mesenteric vein, and 4) right lower quadrant cecum. Two attending radiologists, one pediatric and one abdominal radiologist, independently reviewed the MR images. The pediatric radiologist reviewed images from UGI (considered the gold standard) to determine the intestinal rotation for each case. Validation of the criteria was performed on new patients imaged through January 2016.ResultsThe original cohort included 109 MRIs (15 chest, 41 spine and 53 abdomen) done on 109 patients (42% males, mean age: 10.2 years). If each of the 4 anatomical questions were answered “yes” (4-YES), specificity was 100% for each radiologist and malrotation was appropriately excluded. Using the 4-YES criteria, the pediatric radiologist excluded malrotation in 71 patients (65%) and the abdominal radiologist excluded it in 65 (60%), with concurrence for 57 patients. Validation of the 4-YES criteria in 23 new patients appropriately proved the 4-YES rule, with neither labeling the one new malrotation case 4-YES.ConclusionIf a radiologist can confidently answer “yes” to the four questions evaluated in this study, then intestinal rotation can be safely considered normal. Normal bowel rotation should be commented upon in MRI reports when these four anatomical locations are imaged, thus helping patients avoid unnecessary UGI and radiation exposure.

Imaging Appearances of Musculoskeletal Developmental Variants in the Pediatric Population

Variations in musculoskeletal development in children are commonly encountered. These variants often have a confusing appearance on imaging and may simulate pathologic conditions. However, in many instances, these normal variants have certain features that allow for confident determination of the benign nature of these entities. An awareness of the characteristic imaging features is therefore important for radiologists. In this review, we focus on 4 specific categories of variants in the development: (1) variations in the normal ossification of skeletal structures, (2) the appearance of tendinous and ligamentous insertions in the developing skeleton, (3) overlapping lines that can be confused with fractures or other pathologic conditions, and (4) variant orientation of normal bones. We review the etiology and imaging appearance of these entities and also describe methods of differentiating these benign entities from pathologic lesions. Although in certain cases, correlation with clinical parameters is needed to confidently diagnose the lesion as benign, in many cases, an appreciation of the characteristic imaging features alone would suffice and prevent a potentially costly workup.